I installed both the Opp Alert Coponent and the ContactsToday Component from the Trailhead Module "Working with Custom Lightning Components". However, they are not available to add as components in the Lightning App Builder. I've tried uninstalling an reinstalling, with no luck. The "Custom Components" section in Lightning App Builder shows 0.

Any help would be appreciated - I've had nothing but technical difficulties with this module and I want to earn that darn badge already!